Ratchet mechanism.



JOSEPH B. SMYTHE, OF COATICOOK, QUEBEC, CANADA.

RATCHET MECHANISM.

Specification of Letters Patent.

Patented Mar. 17!, 1914.

\ Application filed June 10, 1911. Serial No. 632,5J 0.

and useful Improvements in Ratchet Mech-- anism, of which the following is a specification.

This invention relates to ratchet mechanism, pawls and ratchets, particularly adapted. for use with lifting jacks, andparticularly to that class of jacks which are known as ratchet screw jacks, and which are manipulated by an operating handle carrying a double ended pawl, either end of which is adapted to engage with the ratchet wheel on an operating shaft. v

The object of thepresent invention is to provide an increased working surface between the pawl and the ratchet wheel, thereby obviating the danger of splitting the ratchets when in operation, and make it possible to operate the ratchet mechanism with a decreased movement of the operatinglever.

The invention consists in'providing theoperating lever with a socket having a trans verse slot in which is positioned the ratchet wheel secured to the shaft of the operating gear, and interposing between said ratchet wheel and. one wall of the socket a recipro- I eating pawl having'a set of teeth at each end' thereof, either of which is adapted to be brought into position to coact with the ratchet teeth to efle'ctthe raising or lowering of the jack as desired.

The invention further consists in certain novel features of construction and arrangement of parts which will be thoroughly understood by reference to the description of the drawings and to the claims hereinafter given.

Of the drawings:-Figure 1 represents a vertical section of a jack embodying the fea tures of the present invention. Fig. 2 rep resents a section of the gear operating mech- ,anism, the cutting plane being on line 22 on Figs. 1 and 3. Fig. 3 represents a vertical sectionofthe same, the cutting plane being on line 33 on Fig. 2, and Fig. 4 repre-v sents a transverse vertical section of the same, the cutting plane being on line 44 on Fig. 2.

Similar characters designate like parts throughout the several figures of the draw- 'ings.

In the drawings, 10 represents a suitable base supporting the stationary standard 11 over the outer periphery of which is fitted a movable sleeve 12,. to the upper end of which 1s threaded a head 13. In the upper end of the head 13 is mounted a plate 14, between the underface of which and the upper face of a beveled gear 15 is interposed a plurality of anti-friction members 16. The gear 15 is splined to the reduced upper end of a screw 17, the threaded end of which is threaded to a nut 18 mounted in the upper end of the standard 11. The gear 15'meshes with the gear 19 secured to or formed upon a revoluble shaft 20 mounted in a bearing 22 on the side of the movable member 12. To the reduced end of the revoluble shaft 20 is splined or otherwise secured the ratchet wheel 23, positioned within a slot 24 of a socket mem ber 25. This socket member 25 when in use has inserted'therein a handle 26 as indicated in dotted lines in Fig. 2 of the drawings, which handle may be moved by the operator to cause an oscillation of the socket member 25 about the shaft 20 upon which it is free to move in either direction, said socket member being retained in position upon said shaft 20 by means of a cotter pin or similar member 27. The ratchet wheel 23 is provided throughout its periphery with a plurality of V-shaped teeth 28. Interposed between this ratchet wheel 23 and one end face 29 of the slot 24 is a reciprocating wedge member 30.

One face of the member 30 is fiat and bears against the fiat face 29 of the slot 24, while the opposite face is provided at either end with a plurality of V-shaped teeth 31. Between these sets of teeth 31 is a connecting portion 32 having a short fiat face 33 parallel to the back face of the member 30, and normally in contact with the ends of the teeth 28. Each set of teeth 31 is arranged in the arc of a circle, the radius of which is the same as that of the ratchet wheel 23, so that when either set of teeth 31 are in engagement with the ratchet teeth 28, all said teeth accurately fit one another and the working surface is thereby greatly increased over a ratchet mechanism such as has usually been used, in which a single pawl coacts with the ratchet teeth. This construction insures a i better grip for operating the jack and owing to the increased gripping surface there is no splitting strain on t e mechanism, as when the pawl is in action it wedges itself between the ratchet wheel and the wall 29 of I the arrow-thereon, the ratchet teeth 31 will multiplication, of power,

the wall of easilyto 1permit the teeth topasson the reso coact with the ratchet teeth 28 as to cause the member 30 to become wedged between the ratchet wheel 23 and the wall 29 and insure a rotary movement of the shaft 20, while permitting, in the return movement of the socket 25, the teeth 31 to pass over the teeth 28, preparatory to securing another grip thereon. This slight movement of the member 30 to permit its teeth to pass the teeth of the ratchet wheel during the return movement is effected by means of the notch 34 cut in the side face of the pawl member 30, and coacting with the V-shaped end of-a locking member 35 positioned in a recess in the socket member 25 and pressed inwardly into contact with one wall of the notch 34: by

means of the spring 36. During the return movement of the socket the locking member 35 will be retracted slightly against the ten. sion of the spring 36 to permit the teeth of the two members to pass one another. The locking member 35 is prevented from turning in'its recess and from beingaccidentally displaced therefrom by means of the screw 37. When it is desired to lower the jack, the member 30 is pressed through the slot in the socket 25 until the notch 38 engages the locking member 35, thereby bringing the other set of teeth 31 into action. It is obvious that during the raising and lowering of the handle 26 the reciprocating pawl member 30 will automatically engage and disengage the ratchet either when'lowering or raising the jack. In order to reduce the frictional contact between the member 30 and the-wall 29 as it reciprocates in the slot in the socket 25, portions of the rear face of said member are cut away as indicated at 38, this also serving to reduce the weight of the pawl member.

In the ordinary ratchet mechanism where a single ploint on the pawl is used for liftin' and'anot er single po nt on the pawl is use for lowering, there is always a great danger of splitting the ratchets owing to the great while in the present construction,- with the increased -area of the grippin surface, this danger is wholly overcome. 7 ile the action 0 the device is very powerful, owing to the pawl when in opera-. tion wedging itself between the ratchet and the slot, the pawl releases very turn stro -Another advantage is-that the back lash in the present construction is greatly reduced over that of the ordinary pawl-and rathet in general use. ,Moreo'ver,

owing to the increased number of teeth in the pawl in engagement with the ratchet, the

lever may be worked in a much smaller space than in the ratchet mechanisms generally used.

It is believed that the operation and many advantages of the invention will be thoroughly understood from the foregoing. Having thus described my. invention, I

claim:

1. In a device of the class described, thecombination of a spindle, an oscillating lever on) said spindle-provided with a socket havin" a transverse slot therein one wall of which is straight and unobstructed; a wheel within said slot secured to said spindle and provided with a serrated peripheral surface; a slidable wedge member in. said slot restricted'in its movement to a path tangen- .tial to said wheel by a flat face contacting with said straight wall'and provided on its opposite face with a curved serrated surface coacting with the periphery of said wheel; and means providing a limited sliding movement of said wedge member during each oscillation of said lever.

' 2. In a device of the class described, the combination of a spindle, an oscillating lever on said spindle provided with a socket having a transverse slot therein one wall of which is straight and unobstructed; a wheel within said slot secured to said spindle and provided with a serrated peripheral surface; a slidable double-ended wedge member in said slot having a flat face contacting with said straight wall and thereby restricted in its movement to a path tangential to said wheeland provided'on its opposite face with a curved serrated surface at each end either of which is adapted to coact with the periphery of said wheel; and means providing a limited sliding movement of said wedge member during each oscillation of said lever. p

3. In a device of the class described, the combination of a spindle; an oscillating lever on said spindle provided with a socket having a transverse slot therein having parallel unobstructed end walls; a wheel within'said slot secured to said spindle and provided with a serrated peripheral surace; a slidable double-ended wedge member in said slot having a flat base contactin with the outer end wall of said slot an thereby restricted in its movement. to a path tangential to said wheel and provided on its opposite face with a curved serrated surface at each end either of which is adapted to coact with the periphery of said wheel, said curved-serrated surfaces being connected by a flat face contacting with the periphery of said wheel; and means providin a limited sliding movement of said wedge member during each oscillation of said lever.

having a transverse slottherein; a wheel within said slot secured to said spindle and provided with a serrated peripheral surface; a slidable double-ended wedge memher in said slot restricted in its movement to a path tangential to said wheel and provided with a curved serrated surface at each end either of which is adapted to coact with the periphery of said wheel, said member being provided with two notches intermediate its ends; and means cooperating with eitherof' saidnotches to retain said member in position for one selected curved serrated surface to coact with said wheel while permitting a limited reciprocation to said member dur- .ing each oscillation of said lever.

5. In a device of the class described, the combination of a spindle; an oscillating lever'on said spindle provided with a socket with a transverse slot therein; a ratchet wheel within said slot secured to said spindle and provided with V-teeth; a slidable member in said slot provided with two sets of; V-teeth adapted to coact independently with i said ratchet teeth and having two notches therein; and a spring-pressed member having an end adapted to engage either notch which end is of less width than that of the coacting notch.

6. In a device of the class described, the

combination of a spindle; an oscillating leveron said spindle provided with a socket with a transverse slot therein having parallel unobstructed end walls; a wheel within said slotsecured to said spindle provided with a serrated peripheral surface; a slidable double ended wedge member in said slot normally having a limited movement in a straight path with its base contacting with the outer end wall of said slot and provided at each end of its opposite face with a curved serrated surface, said curved surfaces being curved serrated surfaces adapted to coact independently with said wheel periphery and having two notches therein; and a spring pressed member having an end adapted to engage either notch which end is of less width than that of the coacting notch.

8. In a device of the class described, the combination of a spindle; an oscillating lever on said spindle provided with a socket with a transverse slot therein; a wheel within said slot secured to said spindle provided with a serrated peripheral surface; a slidable member in said slot provided with two curved serrated surfaces adapted to coact independently with said Wheel periphery and having two notches therein; a spring pressed member having a tapered end adapted to engage either notch; and a stop preventing the tapered end ofsa1d spr ng pressed member extending to the bottom of said notches thereby permitting a limited movement to said slidable member.

Signed by me at 4 Post Office Sq., Boston,

Mass, this 19th day of May, 1911.

JOSEPH SMYTHE.

Witnesses:

WALTER E. LoMBARD, NATHAN O. LOMBARD. 

